basic_string::resize
Specifies a new size for a string, appending or erasing elements as required.
void resize(
size_type _Count,
);
void resize(
size_type _Count,
_Elem _Ch
);
Parameters
_Count
The new size of the string._Ch
The value that appended characters are initialized with if additional elements are required.
Remarks
If the resulting size exceeds the maximum number of characters, the form throws length_error.
Example
// basic_string_resize.cpp
// compile with: /EHsc
#include <string>
#include <iostream>
int main( )
{
using namespace std;
string str1 ( "Hello world" );
cout << "The original string str1 is: " << str1 << endl;
basic_string <char>::size_type sizeStr1;
sizeStr1 = str1.size ( );
basic_string <char>::size_type capStr1;
capStr1 = str1.capacity ( );
// Compare size & capacity of the original string
cout << "The current size of original string str1 is: "
<< sizeStr1 << "." << endl;
cout << "The capacity of original string str1 is: "
<< capStr1 << "." << endl << endl;
// Use resize to increase size by 2 elements: exclamations
str1.resize ( str1.size ( ) + 2 , '!' );
cout << "The resized string str1 is: " << str1 << endl;
sizeStr1 = str1.size ( );
capStr1 = str1.capacity ( );
// Compare size & capacity of a string after resizing
cout << "The current size of resized string str1 is: "
<< sizeStr1 << "." << endl;
cout << "The capacity of resized string str1 is: "
<< capStr1 << "." << endl << endl;
// Use resize to increase size by 20 elements:
str1.resize ( str1.size ( ) + 20 );
cout << "The resized string str1 is: " << str1 << endl;
sizeStr1 = str1.size ( );
capStr1 = str1.capacity ( );
// Compare size & capacity of a string after resizing
// note capacity increases automatically as required
cout << "The current size of modified string str1 is: "
<< sizeStr1 << "." << endl;
cout << "The capacity of modified string str1 is: "
<< capStr1 << "." << endl << endl;
// Use resize to downsize by 28 elements:
str1.resize ( str1.size ( ) - 28 );
cout << "The downsized string str1 is: " << str1 << endl;
sizeStr1 = str1.size ( );
capStr1 = str1.capacity ( );
// Compare size & capacity of a string after downsizing
cout << "The current size of downsized string str1 is: "
<< sizeStr1 << "." << endl;
cout << "The capacity of downsized string str1 is: "
<< capStr1 << "." << endl;
}
The original string str1 is: Hello world
The current size of original string str1 is: 11.
The capacity of original string str1 is: 15.
The resized string str1 is: Hello world!!
The current size of resized string str1 is: 13.
The capacity of resized string str1 is: 15.
The resized string str1 is: Hello world!!
The current size of modified string str1 is: 33.
The capacity of modified string str1 is: 47.
The downsized string str1 is: Hello
The current size of downsized string str1 is: 5.
The capacity of downsized string str1 is: 47.
Requirements
Header: <string>
Namespace: std